Since the use of the public Internet has become increasingly popular as one of the world's premier sources of communications, new and innovative technologies have been developed to tap into the Internet's vast resources. This new form of communication has sprouted numerous technological innovations and services that benefit both consumers and industry. One of these innovations is the transmission of voice over the Internet.
In the mid to late 1970s, experiments in the transmission of voice over the Internet were conducted as part of an ongoing research program sponsored by the U.S. Defense Advanced Research Projects Agency (DARPA). In the mid 1980s, UNIX-based workstations were used to conduct regular audio/video conferencing sessions in modest quantities over the Internet. These experimental applications were extended in the late 1980s with larger scale, one-way multicasting of voice and video. In 1995 a small company, VocalTec Communications Ltd., commercially introduced a software package that was capable of providing two way voice communications between multi-media PCs connected to the Internet.
Telephony over the Internet offers users a low cost service that is distance and border insensitive. For the current cost of Internet access (at low hourly rates or unlimited use flat fees) the caller can hold a voice conversation with another PC user connected to the Internet. In the case where one or both ends have flat fee connections to the Internet, the call is free of additional charges. This makes Internet telephony an attractive alternative to cost conscious consumers.
Unfortunately, Internet telephony or Voice over Internet Protocol (VOIP) suffers from a number of problems. The voice quality across the Internet is not as good as typical telephone toll quality and there are significant delays experienced during the conversation. In addition, Internet telephones do not have the benefit of the plethora of added services that are available through standard switched telephones.